Vehicle Seat Back Frame Fragile Portion Design
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Solution Overview
Problem
Existing vehicle seat designs fail to effectively absorb collision energy during rear collisions, leading to inadequate load reduction on occupants and excessive backward inclination, which compromises comfort and posture.
Innovation Solution
A vehicle seat with a frame side portion featuring a first and second fragile portion, designed to deform under impact, allowing controlled energy absorption while maintaining rigidity in normal use and regulating deformation to minimize posture disruption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the seat back frame is made rigid to ensure stability during normal use, then the structural strength is improved, but the ability to absorb collision energy through deformation is degraded
Solution Approach 1:
The side frame is segmented into multiple regions with different rigidities: a high-rigidity region for normal structural support and a low-rigidity region with a fragile portion for collision energy absorption. This segmentation allows the frame to perform differently under normal use versus impact conditions, resolving the contradiction between strength and energy absorption.
Solution Approach 2:
The fragile portion is created by locally reducing the thickness or cross-sectional area of the side frame at a specific position. This local quality change creates a designated weak point that deforms preferentially during collision, enabling energy absorption while the rest of the frame maintains its structural strength.
2Loss of energy
If the side frame is made deformable to absorb collision energy, then the impact load reduction is improved, but the rigidity during normal use is degraded
Solution Approach 1:
The side frame is divided into a high-rigidity region and a low-rigidity region with the fragile portion. This segmentation ensures that the deformable section only activates under impact conditions, while the high-rigidity region maintains structural stability during normal use, thus resolving the contradiction between impact load reduction and normal rigidity.
3Loss of energy
If the fragile portion is positioned to maximize energy absorption, then the collision energy absorption efficiency is improved, but the backward inclination angle increases excessively
Solution Approach 1:
The fragile portion is positioned at a specific location on the side frame where local deformation can be achieved without causing excessive overall backward inclination. This localized quality change allows efficient energy absorption at the deformation point while limiting the propagation of deformation to the seat back angle, resolving the contradiction between absorption efficiency and posture maintenance.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The seat efficiently absorbs collision energy, ensuring occupant comfort by balancing rigidity and deformation, reducing the impact load and controlling the backward inclination angle, thus enhancing safety and comfort.
Implementation Method 1
the fragile portion is deformed when an impact load is applied thereto
Implementation Method 2
when collision energy generated in the event of a collision is applied thereto
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Provided is a vehicle seat capable of absorbing collision energy while being bent when the collision energy is applied thereto in the event of a rear collision. A vehicle seat S includes a frame side portion 15a which is located at each of right and left sides of a seat back frame 1 and extends in the up and down direction. The frame side portion 15a is provided with a first fragile portion 150A which is formed so as to extend forward from the rear end and a second fragile portion 150B which is formed at a position separated from the first fragile portion 150A in the frame side portion 15a, and the first fragile portion 150A extends toward the formation position of the second fragile portion 150B.